import  java.util.*;

public class ArrayListMagnet{

    public static void main (String[] args) {
        ArrayList<String> a = new ArrayList<String>();
        a.add(0, "zero");
        a.add(1, "one");
        a.add(2, "two");
        a.add(3, "three");
        printAL(a);

        a.remove(2);
        if (a.contains("three")){
            a.add("four");
        }
        printAL(a);

        if(a.contains("two")){
            a.add("2.2");
        }
        if(a.indexOf("four")!=4){
            a.add(4, "4.2");
        }
        printAL(a);
        printAL(a);
    }

    public static void printAL(ArrayList<String> al){
        for (String element : al){
            System.out.print(element + " ");
        }
        System.out.println(" ");
    }
}